hi,

sorry for my amount of posts here recently...I think i'm just starting to understand all the terminology and figure out what i'm looking for!

That said, can someone explain the 'conventional (HD) mattress' foam used by FBM? I understand Latex and Slow Recovery (visco-elastic) foam, but what is this stuff? How does it feel, and does it hold up? Do people use it for the whole mattress or just for bases, etc?

Thank you so much!!

It feels like regular foam. You can sleep directly on it but I found that having the Lux was better for a base.  It is more firm. If you get the R version of either, it will hold up pretty well.

So, if i were to use it as a base, could i put memory foam OR Latex on top? What are the pros/cons to using the 'conventional' foam as a base? Thank you!

It's firmer and will give you the height that you want without losing support.

also,  I recommend getting thinner pieces and stack rather than getting 3 or 4 inches of anything.